Rubber bands are used in many training regimes for physical training, and are often used for home or workplace training, for fitness, preventive, rehabilitative training, and physical therapy. However, no objective method exists for measuring the extent or intensity of the performed training, other than simply counting the number of repetitions carried out by the user. It is estimated that more than 50% of physical-therapy patients have a non-satisfactory compliance with assigned home training.
In practice, physical therapists attempt to control the “training dosage”, by:
1. Choosing between different types of rubber-bands with different force-to-length ratios (elasticity);
2. Adjust the length of the rubber-band;
3. Instruct the patient/user in specific exercises;
4. Instruct the patient/user in the amount of repetitions, speed and breaks during the exercise;
5. Follow up on executed training, by observing or interviewing the patient/user.
Products exist that combine rubber bands with monitoring of hand or limb motion, using accelerometers, gyroscopes or cameras, such as the Nintendo Wii or X-box Kinect. These solutions provide an inaccurate estimation of force or strain, and are not used in practice, for measuring serious or clinical training.
Hence, there is still a need for a simple device that can monitor the exercise performed with a rubber band.